Winner for Best Actor "Manchester By The Sea" Casey Affleck (R) is embraced by his brother Ben Affleck on stage at the 89th Oscars on Feb. 26, 2017 in Hollywood, California.MARK RALSTON/AFP/Getty ImagesOscars 2017: Inside All of the Afterparties

Ben, 44, jumped from his seat to hug Casey, 41, when his name was announced and kissed him on the cheek. "It was very moving. Obviously, my brother, to have him there, it was a nice moment," Casey told reporters in the press room at Hollywood's Dolby Theater. "He didn't actually say anything. He just hugged me. A lot of people have been giving me some grief for not thanking him in the past, but in a friendly way."

The elder Affleck went on to cry as he watched his sibling take the stage. "I saw those tears and I thought maybe I'm just not making a good speech and he was really disappointed. But I think he was probably touched, and I think that we are — I mean, not to brag or anything, but I think we're the only two brothers to win Academy Awards, ever," Casey added.

Ben Affleck, left, congratulates Casey Affleck as he accepts the award for best actor in a leading role for 'Manchester by the Sea' at the Oscars on Sunday, Feb. 26, 2017, at the Dolby Theatre in Los Angeles. Chris Pizzello/Invision/APOscars 2017: Candid Backstage, Audience Moments You Missed

Ben already has two Oscars under his belt. He won for best original screenplay for Good Will Hunting in 1998 and best picture for Argo in 2013. (He directed, starred in and produced the drama.)

"I've learned a lot from him because he's been through a lot in this business and ups and downs and been under-appreciated and then it's been proven how great he is," Casey continued backstage. "It's been an advantage to be able to watch someone you love and you know so well go try to navigate the very tricky, rocky, sometimes hateful waters of being famous."

Casey gave a shout-out to Ben during his speech, but forgot to thank two important people — his sons, Indiana, 12, and Atticus, 8, whom he shares with estranged wife, Summer Phoenix. "I didn't thank my children, which is something that I'll probably never ever live down," he told reporters. "About three seconds after I made it backstage, my phone rang and my son said, 'You didn't even mention us.' And my heart just sank. So, you know, that probably would have been the most meaningful thing I could have said and I failed."

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!